Specific Bacteria Research Articles

Increasing degree of substitution inhibits acetate while promotes butyrate production during in vitro fermentation of citric acid-modified rice starch

Citric acid-modified starch functions as a resistant starch, while the combined effects of its fine molecular structure and degree of substitution on gut microbiota are not well understood. To this end, citric acid-modified starches with varying degrees of substitution were synthesized from rice starches with distinct molecular structures and their impact on gut microbiota composition and short-chain fatty acid (SCFA) production was analyzed. Notably, rice starch with a higher degree of substitution significantly reduced acetate production, while promoted butyrate production. Correlation analysis further suggested that amylopectin chains with 12 < DP ≤ 36 and amylose chains with 100 < DP ≤ 500 alter the growth of Faecalibacterium_prausnitzii and Bacteroides_vulgatus, consequentially determining the production of SCFAs. Collectively, these findings indicate that citric acid-modified rice starch with different degrees of substitution can target specific gut bacteria and SCFA production, thus conferring beneficial impact on human health.

Analysis of spatial structure and singularity of microbial biogeochemical anomalies in the Taiwan Strait Basin

The abundance of specific hydrocarbon-oxidizing bacteria (MV value) in surface soil is closely linked to the concentration of thermogenic light hydrocarbons found in the underlying layers. The identification of these bacteria using specific detection techniques offers unique insights into microbiological anomalies associated with oil and gas, underscoring the significance of delineating microbiological geochemical anomalies in the exploration process. Accurate determination of the anomaly range is crucial for forecasting potential oil and gas reservoirs. In this study, a variety of fractal and geological statistical methods were employed to analyze microbiological geochemical data from the Taiwan Strait Basin. The multifractal approach allows for the simultaneous assessment of spatial autocorrelation and singularity in geochemical fields, with the fractal distribution reflecting the localized enrichment and depletion patterns of microbiological geochemical elements in rocks and other substrates. Geological statistical methods, such as the variation function, enable the assessment of spatial autocorrelation in geochemical and geophysical fields. The results indicate that microbiological anomalies in the Jiulongjiang Depression are mainly concentrated in the southwestern part of the study area, with some anomalies also observed in the central region. Conversely, microbiological anomalies in the Jinjiang Depression are predominantly located in the southern portion of the study area. Microbiological anomalies in the study area (Jinjiang Depression and Jiulongjiang Depression) exhibit a northeast-southwest strip distribution, aligning with the trend of the depressions and faults, suggesting that faults could influence the distribution of oil and gas resources in the region. Based on microbiological statistical analyses, the Jiulongjiang Depression shows better potential for oil and gas prospects compared to the Jinjiang Depression, guiding future research efforts in the Jiulongjiang Depression.

7964 Manipulation of the Gut Microbiome Using Antibiotics Is Associated With Sex-Specific Reductions in Systemic Testosterone Levels in Rats

Abstract Disclosure: G. Parodi: None. G. Leite: None. W. Morales: None. S.R. Weitsman: None. G.M. Barlow: None. M. Sanchez: None. M. Pimentel: None. M. Villanueva-Millan: None. M. Pimentel: None. R. Mathur: None. The gut microbiome has impacts on metabolic endocrine and reproductive functions. It is known that specific bacteria can impact host metabolism by synthesizing, secreting, and/or metabolizing sex-related hormones. However, the impacts of gut bacterial biosynthesis and/or metabolism of steroids on host metabolism and reproduction have not been fully addressed. In this study we challenged the gut microbiome of wild-type male and female rats with broad-spectrum antibiotics and examined the effects on circulating testosterone levels. Methods: Male (M) and female (F) Sprague-Dawley rats (8 weeks old) were housed with phytoestrogen-free bedding and received a phytoestrogen-free diet with water from glass bottles. Rats were given a combination of vancomycin (0.5g/L), ampicillin (1g/L), neomycin (1g/L), and metronidazole (1g/L) in their water for 8 days, and then returned to normal drinking water for another 13 days. Control rats were given normal water throughout the study. Serum and stool samples were collected before the start of antibiotics (baseline), on day 8 of antibiotics (AbxD8), and at 13 days post-removal of antibiotics (PAbxD13). Stool total DNA was extracted with the MagAttract PowerSoil DNA KF kit and quantified on a Qubit. Circulating testosterone levels were analyzed on a Luminex platform. Paired-ANOVA test was used to determine changes in testosterone levels in each group over time. Results: A total of 31 rats (M=16, F=15) received antibiotics, and 28 (M=14, F=14) were controls. Antibiotic exposure resulted in significant decreases in total stool DNA quantity in both male and female exposed rats relative to controls on AbxD8 (P&amp;lt;0.0001), which returned to baseline levels by PAbxD13. Antibiotic exposed male rats had a continuous decrease in testosterone levels throughout the timepoints collected (baseline: 5.78±2.74 ng/mL, AbxD8: 3.11±2.46 ng/mL, PAbxD13: 2.55±1.80 ng/mL, P=0.0027), however, in control male rats, circulating testosterone levels remained stable throughout the timepoints analyzed (baseline: 3.81±1.73 ng/mL, AbxD8: 3.72±1.12 ng/mL, PAbxD13: 3.92±3.38 ng/mL, P=0.49). There was no effect on circulating testosterone levels in female rats, with both groups, control and exposed, following the same cyclical pattern throughout the timepoints analyzed. Conclusions: Antibiotic depletion of the gut microbiome is associated with changes in systemic levels of testosterone in rats. These changes are sex-specific, and only detected in males. These results suggest a potential involvement of the gut microbiome in testosterone metabolism that is sex-specific. Presentation: 6/1/2024

7964 Manipulation of the Gut Microbiome Using Antibiotics Is Associated With Sex-Specific Reductions in Systemic Testosterone Levels in Rats

Abstract Disclosure: G. Parodi: None. G. Leite: None. W. Morales: None. S.R. Weitsman: None. G.M. Barlow: None. M. Sanchez: None. M. Pimentel: None. M. Villanueva-Millan: None. M. Pimentel: None. R. Mathur: None. The gut microbiome has impacts on metabolic endocrine and reproductive functions. It is known that specific bacteria can impact host metabolism by synthesizing, secreting, and/or metabolizing sex-related hormones. However, the impacts of gut bacterial biosynthesis and/or metabolism of steroids on host metabolism and reproduction have not been fully addressed. In this study we challenged the gut microbiome of wild-type male and female rats with broad-spectrum antibiotics and examined the effects on circulating testosterone levels. Methods: Male (M) and female (F) Sprague-Dawley rats (8 weeks old) were housed with phytoestrogen-free bedding and received a phytoestrogen-free diet with water from glass bottles. Rats were given a combination of vancomycin (0.5g/L), ampicillin (1g/L), neomycin (1g/L), and metronidazole (1g/L) in their water for 8 days, and then returned to normal drinking water for another 13 days. Control rats were given normal water throughout the study. Serum and stool samples were collected before the start of antibiotics (baseline), on day 8 of antibiotics (AbxD8), and at 13 days post-removal of antibiotics (PAbxD13). Stool total DNA was extracted with the MagAttract PowerSoil DNA KF kit and quantified on a Qubit. Circulating testosterone levels were analyzed on a Luminex platform. Paired-ANOVA test was used to determine changes in testosterone levels in each group over time. Results: A total of 31 rats (M=16, F=15) received antibiotics, and 28 (M=14, F=14) were controls. Antibiotic exposure resulted in significant decreases in total stool DNA quantity in both male and female exposed rats relative to controls on AbxD8 (P&amp;lt;0.0001), which returned to baseline levels by PAbxD13. Antibiotic exposed male rats had a continuous decrease in testosterone levels throughout the timepoints collected (baseline: 5.78±2.74 ng/mL, AbxD8: 3.11±2.46 ng/mL, PAbxD13: 2.55±1.80 ng/mL, P=0.0027), however, in control male rats, circulating testosterone levels remained stable throughout the timepoints analyzed (baseline: 3.81±1.73 ng/mL, AbxD8: 3.72±1.12 ng/mL, PAbxD13: 3.92±3.38 ng/mL, P=0.49). There was no effect on circulating testosterone levels in female rats, with both groups, control and exposed, following the same cyclical pattern throughout the timepoints analyzed. Conclusions: Antibiotic depletion of the gut microbiome is associated with changes in systemic levels of testosterone in rats. These changes are sex-specific, and only detected in males. These results suggest a potential involvement of the gut microbiome in testosterone metabolism that is sex-specific. Presentation: 6/1/2024

Enhanced anaerobic digestion for energy recovery from brewery wastewater employing nano zero-valent iron loaded biochar prepared by residual sludge

Anaerobic digestion is an effective wastewater energization technology, but suffers from low energy conversion efficiency. In this study, a novel biochar was successfully prepared by incorporating extracellular polymeric substances (EPS) to residual sludge, and the anaerobic digestion performance could be significantly improved by employing this biochar loaded with nano zero-valent iron (NZVI@EPSBC). In comparison to the control, the cumulative methane production with 100 mg/L NZVI@EPSBC was raised by approximately 1.4-fold. The NZVI@EPSBC did not significantly change the morphology of the inoculated granular sludge, but induced the secretion of proteins and humic substances in the extracellular EPS, which are beneficial for carbon conversion and extracellular electron transport at the microscopic scale. Meanwhile, the quantitative analysis of the electron transport system also confirmed that NZVI@EPSBC could significantly improve the electron transfer efficiency in microbial respiratory chain throughout the experimental cycle, in which the highest respiratory efficiency increase of 26.51 % at 48 h. Taxonomic analysis of microbial communities showed that NZVI@EPSBC exhibited complete retention of bacteria and archaea compared to the raw sludge, while realizing an efficient cooperative pattern of syntrophic bacteria by regulating the relative abundance of specific functional bacteria, like Anaerolineaceae and Methanosaeta. Overall, the study offers a valuable strategy for achieving resourcefulness of residual sludge and EPS along with facilitating efficient energy recovery from brewery wastewater.

Tumor-colonized Streptococcus mutans metabolically reprograms tumor microenvironment and promotes oral squamous cell carcinoma

BackgroundOral squamous cell carcinoma (OSCC) remains a major death cause in head and neck cancers, but the exact pathogenesis mechanisms of OSCC are largely unclear.ResultsSaliva derived from OSCC patients but not healthy controls (HCs) significantly promotes OSCC development and progression in rat models, and metabolomic analyses reveal saliva of OSCC patients but not HCs and OSCC tissues but not adjacent non-tumor tissues contain higher levels of kynurenic acid (KYNA). Furthermore, large amounts of Streptococcus mutans (S. mutans) colonize in OSCC tumor tissues, and such intratumoral S. mutans mediates KYNA overproductions via utilizing its protein antigen c (PAc). KYNA shifts the cellular types in the tumor microenvironment (TME) of OSCC and predominantly expedites the expansions of S100a8highS100a9high neutrophils to produce more interleukin 1β (IL-1β), which further expands neutrophils and induces CD8 + T cell exhaustion in TME and therefore promotes OSCC. Also, KYNA compromises the therapeutic effects of programmed cell death ligand 1 (PD-L1) and IL-1β blockades in oral carcinogenesis model. Moreover, KYNA-mediated immunosuppressive program and aryl hydrocarbon receptor (AHR) expression correlate with impaired anti-tumor immunity and poorer survival of OSCC patients.ConclusionsThus, aberration of oral microbiota and intratumoral colonization of specific oral bacterium such as S. mutans may increase the production of onco-metabolites, exacerbate the oral mucosal carcinogenesis, reprogram a highly immunosuppressive TME, and promote OSCC, highlighting the potential of interfering with oral microbiota and microbial metabolism for OSCC preventions and therapeutics.5ViVJ5sCbraGF_6Zi1UXojVideo

Reclamation of co-pyrolyzed dredging sediment as soil cadmium and arsenic immobilization material: Immobilization efficiency, application safety, and underlying mechanisms

The safe management of toxic metal-polluted dredging sediment (DS) is imperative owing to its potential secondary hazards. Herein, the co-pyrolysis product (DS@BC) of polluted DS was creatively applied to immobilize soil Cd and As to achieve DS resource utilization, and the efficiency, safety, and mechanism were investigated. The results revealed that the DS@BC was more effective at reducing soil Cd bioavailability than the DS was (58.9–73.2% vs. 21.8–27.4%), except for the dilution effect, whereas the opposite phenomenon occurred for soil As (25.5–35.7% vs. 35.7–42.8%). The DS@BC immobilization efficiency was dose-dependent for both Cd and As. Soil labile Cd and As were transformed to more stable fractions after DS@BC immobilization. DS@BC immobilization inhibited the transfer of soil Cd and As to Brassica chinensis L. and did not cause excessive accumulation of other toxic metals in the plants. The appropriate addition of the DS@BC (8%) sufficiently alleviated the oxidative stress response of the plants and enhanced their growth. These findings indicate that the DS@BC was safe and effective for soil Cd and As immobilization. DS@BC immobilization decreased the diversity and richness of the rhizosphere soil bacterial community because of the dilution effect. The DS@BC immobilized soil Cd and As via direct adsorption, and indirect increasing soil pH, and regulating the abundance of specific beneficial bacteria (e.g., Bacillus). Therefore, the use of co-pyrolyzed DS as a soil Cd and As immobilization material is a promising resource utilization method for DS. Notably, to verify the long-term effects and safety of DS@BC immobilization, field trials should be conducted to explore the effectiveness and risk of harmful metal release from DS@BC immobilization under real-world conditions.

Oral Microbiome and Cognition Among Black Cancer Caregivers

Abstract Background Despite known links between oral health and dementia and the growing understanding of the role of the human microbiome in health, few studies have explored the relationship between the oral microbiome and cognition. Additionally, there is a notable absence of research on how the oral microbiome is associated with cognitive function in Black adult caregivers of cancer patients despite their elevated risk for both oral disease and cognitive impairment. Objectives This study aimed to characterize the oral microbiome of Black caregivers of people living with cancer and explore the association of the oral microbiome with cognitive performance. Methods Thirty-one self-identified Black or African American caregivers of cancer patients in the greater metropolitan Atlanta area participated in the study. They provided oral microbiome samples. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA), depressive symptoms with the Center for Epidemiological Studies Depression Scale, and individual race-related stress with the Index of Race-Related Stress–Brief. Salivary microbiome diversity was analyzed using alpha and beta diversity metrics, and taxa associated with cognition were identified through differential abundance testing, adjusting for potential confounders. Results The mean age of participants was 54.8 years. MoCA scores ranged from 18 to 30, with a mean of 25. Participants were categorized into normal cognition (MoCA ≥26, n = 12) and low cognition (MoCA &lt;26, n = 16) groups. Education level and individual race-related stress were associated with cognition group and were controlled for in the oral microbiome analysis. Alpha and beta diversity analyses showed no significant overall differences between cognition groups. Differential abundance testing suggested 48 taxa were associated with cognition status, many of which are known to be associated with periodontal disease and cognition. Discussion This study revealed associations between cognition status and specific oral bacteria, many of which are known to be associated with periodontal disease and cognitive impairment. These findings underscore the complex relationship between oral health and cognitive function, suggesting a need for further research to develop oral microbiome profiles capable of identifying individuals at risk for cognitive decline and guiding targeted interventions for promoting overall well-being and cognitive health.

Prevalence of Specific Hygienic Indicator Bacteria in cattle Slaughterhouses of different Capacity in Egypt

Prevalence of Specific Hygienic Indicator Bacteria in cattle Slaughterhouses of different Capacity in Egypt

5-aminosalicylic acid alleviates colitis and protects intestinal barrier function by modulating gut microbiota in mice.

5-aminosalicylic acid (5-ASA) is widely used in the treatment of ulcerative colitis (UC), but its anti-inflammatory mechanism is complex and has not been fully understood. DSS model was used to test the effect of 5-ASA. Tight junction and Ki-67 were detected by western blot, immunofluorescence, and immunohistochemistry or qPCR. 16S rRNA gene sequencing of gut microbiota and subsequent bioinformatics and statistical analysis were performed to identify the specific bacteria which were associated with the treatment effect of 5-ASA. GC-MS was performed to test short-chain fatty acids (SCFAs). Antibiotic-treated mice were used to demonstrate the key role of endogenous gut microbiota. Here, we found that 5-ASA alleviated dextran sulfate sodium (DSS)-induced colitis in mice. Moreover, 5-ASA significantly repaired the intestinal barrier. At the molecular level, 5-ASA markedly raised the expression of tight junction proteins including JAM-A and occludin and cell proliferation marker Ki-67 in mice. In addition, bacterial 16S rRNA gene sequencing and bioinformatics analysis showed that 5-ASA significantly modulated the DSS-induced gut bacterial dysbiosis. In detail, it stimulated the growth of protective bacteria belonging to Faecalibaculum and Dubosiella, which were negatively correlated with colitis parameters, and blocked the expansion of pro-inflammatory bacteria such as Escherichia-Shigella and Oscillibacter, which were positively correlated with colitis in mice. Meanwhile, 5-ASA increased the cecal acetate level. Most notably, 5-ASA was no longer able to treat colitis and reverse gut barrier dysfunction in antibiotic-treated mice that lacked endogenous gut microbiota. Our data suggested that the anti-inflammatory activity of 5-ASA required the inherent intestinal flora, and the gut microbiota was a potential and effective target for the treatment of ulcerative colitis.

Foliar application of biostimulants improves nutritional and bioactive quality of walnuts.

Owing to their health benefits, walnuts are attracting interest as a good option for nutritious meals, thereby promoting their production. Furthermore, the adoption of ecologically and environmentally friendly agriculture strengthens biostimulant use as a sustainable complement to traditional fertilizers. This study evaluated the effects of different foliar-applied biostimulants in walnut tree orchards, in northeastern Portugal, on walnuts' chemical composition and bioactivity. Walnut samples were rich in fat (particularly the polyunsaturated linoleic acid), dietary fiber and protein. Sucrose was the most prevalent soluble sugar, followed by glucose and fructose. Studied samples also showed an antioxidant activity comparable (or superior) to that of Trolox. Some plant biostimulants (e.g. Sprint Plus®) had a positive impact on the nutritional composition of walnuts, more specifically by boosting tocopherol levels, besides improving the bioactivity of walnut extracts against specific bacteria. Overall, this research demonstrated that important quality traits of walnuts can be improved using sustainable agricultural bioproducts and practices. © 2024 Society of Chemical Industry.

Characterisation of potential anti-inflammatory next-generation probiotics resistant to bisphenol A.

The world is witnessing an increasing incidence of chronic non-communicable diseases (NCDs), such as inflammatory bowel disease (IBD), a group of complex gastrointestinal disorders characterised by inflammation. It is believed that environmental factors, such as exposure to pollutants and endocrine-disrupting chemicals (i.e. bisphenol A [BPA]), are playing a role in IBD pathophysiology. New research suggests a potential treatment solution: next-generation probiotic (NGP) strains isolated from human gut microbiota that can biodegrade xenobiotics and thus possibly modulate IBD triggered by these xenobiotics. In this study, we hypothesised that specific BPA-tolerant bacteria would exhibit beneficial, anti-inflammatory properties that could counter the effects of BPA exposure and concomitantly reduce colitis severity. We observed that two such strains, Bacillus sp. AM1 and Paeniclostridium sp., exhibited potential anti-inflammatory properties in vitro and in vivo. First, these bacteria were able to decrease the secretion of interleukin (IL)-8 cytokines by HT-29 cells that had been exposed to the proinflammatory cytokine tumour necrosis factor (TNF)-α. Second, when treated with Bacillus sp. AM1 and Paeniclostridium sp. (this latter had a stronger reducing effect on inflammatory markers), mice with chemically induced colitis displayed lower levels of colon damage, monocyte chemotactic protein 1 (MCP-1), lipocalin-2 (LCN-2), and proinflammatory cytokines (IL-1β and IL-6). Future research should clarify the underlying mechanisms at play and identify potential strategies for counteracting the systemic effects of IBD, including those exacerbated by BPA exposure. Our results suggest that one such strategy could be treatment with BPA-tolerant bacteria that possess anti-inflammatory properties.

Methylated tirilazad may mitigate oligofructose-induced laminitis in horses.

Laminitis is a serious health condition that can cause severe pain and lameness in horses. Due to lack of understanding of laminitis, treatments often fail to achieve the desired results. In recent years, we have begun to recognize that laminitis may involve a complex interaction between local and systemic inflammation. Dysbiosis of the gut microbiota has been linked in the development of systemic inflammation, and our previous findings suggest that the development of laminitis is closely linked to the production of harmful metabolites of the gut microbiota. In addition, it was found that localized lesions in the hoof, especially lamellar injuries, are the most direct cause of laminitis. Matrix metalloproteinases have been found to be strongly associated with the development of laminitis. Recent discovery has found that methylated tirilazad has a role in repairing laminar tissue in vitro. However, its efficacy in horses never has been studied. Therefore, we aimed to investigate the efficacy of methylated tirilazad (product name: PTP-102) in the prevention/treatment of oligofructose-induced laminitis. The results showed that oligofructose successfully induced laminitis in horses, resulting in detreated clinical signs. Blood indices (including inflammation-related indices and other related indices) were significantly increased. Observations of dissection and staining showed significant bleeding, swelling, and damage to hoof tissue. Analysis of the gut microbiota showed a significant decrease in abundance and diversity, and a significant increase in the relative abundance of specific bacteria. Following methylated tirilazad intervention, there were a significant improvement in clinical signs, blood markers and lamellar tissue damage. Additionally, methylated tirilazad positively influenced the gut microbiota structure by reducing the relative abundance of genera closely associated with the development of equine laminitis. This suggests that some of the therapeutic mechanism of methylated tirilazad may be linked to its effects on the gut microbiota. Notably, methylated tirilazad had better effect in the treatment group than the prophylactic group, indicating the post-diagnosis utility of methylated tirilazad for laminitis management.

Abiotic factors shape mosquito microbiomes that enhance host development.

Metazoans rely on interactions with microorganisms through multiple life stages. For example, developmental trajectories of mosquitoes can vary depending on the microorganisms available during their aquatic larval phase. However, the role that the local environment plays in shaping such host-microbe dynamics and the consequences for the host organism remain inadequately understood. Here, we examine the influence of abiotic factors, locally available bacteria, and their interactions on the development and associated microbiota of the mosquito Aedes albopictus. Our findings reveal that leaf detritus infused into the larval habitat water, sourced from native Hawaiian tree "ōhi'a lehua Metrosideros polymorpha, invasive strawberry guava Psidium cattleyanum, or a pure water control, displayed a more substantial influence than either temperature variations or simulated microbial dispersal regimes on bacterial community composition in adult mosquitoes. However, specific bacteria exhibited divergent patterns within mosquitoes across detrital infusions which did not align with their abundance in the larval habitat. Specifically, we observed a higher relative abundance of a Chryseobacterium sp. strain in mosquitoes from the strawberry guava infusion than the pure water control, whereas the opposite trend was observed for a Pseudomonas sp. strain. In a follow-up experiment, we manipulated the presence of these two bacterial strains and found larval developmental success was enhanced by including the Chryseobacterium sp. strain in the strawberry guava infusion and the Pseudomonas sp. strain in the pure water control. Collectively, these data suggest that interactions between abiotic factors and microbes of the larval environment can help shape mosquito populations" success.

Effects of transgenic modification on the bacterial communities in different niches of maize under glyphosate toxicity

Transgenic glyphosate-resistant maize has emerged as a way to expand the use of glyphosate for weed control. Studying the microbiome in the tissues and rhizosphere soil of transgenic plants is vital for understanding the glyphosate-resistant mechanism and optimizing the transgenic design of crops. In our study, the expression of a mutant cp4epsps gene in transgenic maize, which confers tolerance to glyphosate, was performed using the maize variety Xianyu 335 as the genetically modified acceptor line. This transgenic modification did not affect the initial bacterial community in the leaf, stem, or root of maize, but promoted a differential bacterial community in the rhizosphere soil. Under glyphosate application, the abundance of beneficial bacteria involved in N fixation and P solubilization in plant tissues and the rhizosphere soil of glyphosate-resistance maize were higher than those in the glyphosate-sensitive maize. In contrast, the abundance of pathogens had the opposite trend, suggesting that the enhanced health of transgenic maize prevented microbiome deterioration under glyphosate. The re-inoculation of bacterial strains isolated from glyphosate-resistance maize into the leaf and rhizosphere soil of glyphosate-sensitive maize resulted in an enhanced photosynthetic capacity in response to glyphosate, demonstrating the vital role of specific bacteria for glyphosate resistance. Our study provides important evidence of how transgenic maize tolerance to herbicides affects the bacterial communities across the maize niches under glyphosate toxicity.

Improving hydrolysis and acidification by regulating the oxygen status and solid content of lignocellulosic waste: Emphasis on the unsealed environment and harnessing the potential of microbial communities

The recalcitrant nature of lignocellulosic raw materials poses a challenge for current biogas plant operations, where hydrolysis and acidification (HA) are the rate-determining steps. To explore the HA balance and microbial mechanisms according to oxygen status and in conditions with relatively high solid content, we made a simple change to build an unsealed reactor. We found that the hemicellulose degradation rate increased by 149.3 % under unsealed conditions. Under microaerobic conditions (Mi), HA with more than 10 % total solid (TS) content exhibited a carbon loss rate of < 10 % in the first 7 days. In the 15 % TS Mi treatment, the organic acid conversion coefficient was 0.04, and the concentration increased to 7.4 g/L within 2 days. A high solid content was the key factor for ensuring efficient organic acid production in the early stage, whereas Mi affected the middle stage. Multiple methods revealed that abundant Prevotella and Clostridium, as well as rare Bifidobacterium, Sporacetigenium, and specific bacteria, had substantial effects on efficient organic acid production and HA balance. The correlation with Mi was 0.57–0.83. The abundance of hemicellulase genes increased by 18.41 %, and the abundance of pyruvate kinase in Mi increased by 15.55 % compared with the sealed condition, demonstrating that Mi can provide complementary advantages in the HA process. The findings in this study improved the operational quality of conventional HA and anaerobic digestion.

The predictive, preventive, and personalized medicine of depression: gut microbiota and inflammation.

Gut microbiota (GM) is closely associated with the onset of depression, in which inflammation plays an essential role. Identifying specific GM associated with depression and their mechanisms, based on the principles of predictive, preventive, and personalized medicine (PPPM), is a critical step toward achieving targeted prevention and personalized treatment for depression. We hypothesized that both gut microbiota (GM) and cytokines influence the onset of depression, with cytokines acting as mediators of GM effects on depression. To test this hypothesis, we employed univariate Mendelian Randomization (UVMR) analysis to identify GM taxa associated with depression and cytokines and to determine the potential role of the identified GM taxa on these cytokines. Subsequently, multivariate Mendelian randomization (MVMR) was used to infer the mediating role of cytokines between the identified differential genus of GM and depression. Our results indicate that immune imbalance due to intestinal dysbiosis serves as an early risk indicator for the onset of depression. This provides a basis for utilizing non-invasive stool detection of GM for early screening, timely prevention, and personalized treatment of depression. By combining non-invasive stool detection of GM with existing methods, such as psychological questionnaires, we can jointly predict and assess the risk of developing depression. Additionally, formulating personalized treatment protocols that combine probiotics and medication can help transition depression management from reactive medicine to predictive, preventive, and personalized medicine (PPPM). UVMR identified 15 GM taxa and 4 cytokines associated with the onset of depression. Specifically, Romboutsia, Intestinimonas, Ruminococcaceae UCG011, and circulating ADA, IL-18R1 were all inferred to be protective factors against the onset of depression. Conversely, Lachnospiraceae FCS020 group, Streptococcus, Marvinbryantia, VEGF_A, and TNFSF14 were inferred as risk factors for the onset of depression. Further, MVMR validated the mediating role of some cytokines in the effects of GM on depression. Our study highlights the influence of alterations in GM on depression, revealing a mediating role of inflammation. By regulating these specific GM, it is hoped that the clinical treatment of depression can be transformed from traditional medicine to PPPM. With the help of mendelian randomization (MR) method, this study provides support for the wide application of non-invasive stool detection of GM for early screening of depression in clinical and carries out precise treatment based on the screening results, targeting the supplementation of specific bacteria, correcting the immune imbalance to prevent depression, and mitigating or blocking the disease process of depression. The online version contains supplementary material available at 10.1007/s13167-024-00379-z.

Unraveling the role of gut microbiota by fecal microbiota transplantation in rat model of kidney stone disease

Emerging research on the microbiome highlights the significant role of gut health in the development of kidney stones, indicating that an imbalance in gut bacteria or dysbiosis can influence the formation of stones by altering oxalate metabolism and urinary metabolite profiles. In particular, the overabundance of specific bacteria such as Enterococcus and Oxalobacter spp., which are known to affect oxalate absorption, is observed in patients with urolithiasis. This study investigates the effects of gut dysbiosis on urolithiasis through fecal microbiota transplantation (FMT) from patients to rats and its impact on urinary mineral excretion and stone formation. Fecal samples from eight patients with calcium oxalate stones and ten healthy volunteers were collected to assess the gut microbiome. These samples were then transplanted to antibiotic-pretreated Wistar rats for a duration of four weeks. After transplantation, we evaluated changes in the fecal gut microbiome profile, urinary mineral excretion rates, and expression levels of intestinal zonula occluden-1 (ZO-1), SLC26A6 and renal NF-κB. In humans, patients with urolithiasis exhibited increased urinary calcium and oxalate levels, along with decreased citrate excretion and increased urinary supersaturation index. The fecal microbiota showed a notable abundance of Bacteroidota. In rodents, urolithiasis-FMT rats showed urinary disturbances similar to patients, including elevated pH, oxalate level, and supersaturation index, despite negative renal pathology. In addition, a slight elevation in the expression of renal NF-κB, a significant intestinal SLC26A6, and a reduction in ZO-1 expression were observed. The gut microbiome of urolithiasis-FMT rats showed an increased abundance of Bacteroidota, particularly Muribaculaceae, compared to their healthy FMT counterparts. In conclusion, the consistent overabundance of Bacteroidota in both urolithiasis patients and urolithiasis-FMT rats is related to altered intestinal barrier function, hyperoxaluria, and renal inflammation. These findings suggest that gut dysbiosis, characterized by an overgrowth of Bacteroidota, plays a crucial role in the pathogenesis of calcium oxalate urolithiasis, underscoring the potential of targeting the gut microbiota as a therapeutic strategy.

Bacterial co-infection in COVID-19: a call to stay vigilant.

Co-infection with diverse bacteria is commonly seen in patients infected with the novel coronavirus, SARS-CoV-2. This type of co-infection significantly impacts the occurrence and development of novel coronavirus infection. Bacterial co-pathogens are typically identified in the respiratory system and blood culture, which complicates the diagnosis, treatment, and prognosis of COVID-19, and even exacerbates the severity of disease symptoms and increases mortality rates. However, the status and impact of bacterial co-infections during the COVID-19 pandemic have not been properly studied. Recently, the amount of literature on the co-infection of SARS-CoV-2 and bacteria has gradually increased, enabling a comprehensive discussion on this type of co-infection. In this study, we focus on bacterial infections in the respiratory system and blood of patients with COVID-19 because these infection types significantly affect the severity and mortality of COVID-19. Furthermore, the progression of COVID-19 has markedly elevated the antimicrobial resistance among specific bacteria, such as Klebsiella pneumoniae, in clinical settings including intensive care units (ICUs). Grasping these resistance patterns is pivotal for the optimal utilization and stewardship of antibiotics, including fluoroquinolones. Our study offers insights into these aspects and serves as a fundamental basis for devising effective therapeutic strategies. We primarily sourced our articles from PubMed, ScienceDirect, Scopus, and Google Scholar. We queried these databases using specific search terms related to COVID-19 and its co-infections with bacteria or fungi, and selectively chose relevant articles for inclusion in our review.

Temperature, sediment resuspension, and salinity drive the prevalence of Vibrio vulnificus in the coastal Baltic Sea

ABSTRACT The number of Vibrio -related infections in humans, e.g., by Vibrio vulnificus , has increased along the coasts of the Baltic Sea. Due to climate change, vibriosis risk is expected to increase. It is, therefore, pertinent to design a strategy for mitigation of the vibriosis threat in the Baltic Sea area, but a prerequisite is to identify the environmental conditions promoting the occurrence of pathogenic Vibrio spp., like V. vulnificus . To address this, we sampled three coastal Baltic sites in Finland, Germany, and Denmark with salinities between 6 and 21 from May to October 2022. The absolute and relative abundances of Vibrio spp. and V. vulnificus in water were compared to environmental conditions, including the presence of the eelgrass Zostera marina , which has been suggested to reduce pathogenic Vibrio species abundance. In the water column, V. vulnificus only occurred at the German station between July and August at salinity 8.1–11.2. Temperature and phosphate (PO 4 3– ) were identified as the most influencing factors for Vibrio spp. and V. vulnificus . The accumulation of Vibrio spp. in the sediment and the co-occurrence with sediment bacteria in the water column indicate that sediment resuspension contributed to V. vulnificus abundance. Interestingly, V. vulnificus co-occurred with specific cyanobacteria taxa, as well as specific bacteria associated with cyanobacteria. Although we found no reduction in Vibrio spp. or V. vulnificus associated with eelgrass beds, our study underscores the importance of extended heatwaves and sediment resuspension, which may elevate the availability of PO 4 3– , for Vibrio species levels at intermediate salinities in the Baltic Sea. IMPORTANCE Elevated sea surface temperatures are increasing the prevalence of pathogenic Vibrio at higher latitudes. The recent increase in Vibrio -related wound infections and deaths along the Baltic coasts is, therefore, of serious health concern. We used culture-independent data generated from three Baltic coastal sites in Denmark, Germany, and Finland from May to October (2022), with a special focus on Vibrio vulnificus , and combined it with environmental data. Our temporal model shows that temperature, combined with sediment resuspension, drives the prevalence of V. vulnificus at intermediate salinities in the coastal Baltic Sea.